How do I upload a contest log to LoTW?

LoTW takes ADIF, not Cabrillo. Open the .log here, choose Save log as → ADIF, and sign the .adi in TQSL as usual. Digital (DG) QSOs need their mode set first — Cabrillo does not say which digital mode it was.

Is the log uploaded anywhere?

No. The file is read by the page itself, in your browser; nothing is sent to a server.

Can I fix a Cabrillo file here?

You can save it again as Cabrillo with the header filled in from a form and every QSO line written the standard way. To change a QSO itself, edit the file in a text editor or in your logger.

plainfolder → Ham radio → CBR

Open a Cabrillo file — a ham radio contest log

Drop the Cabrillo log and its QSOs open as a table — date, time, call, band, frequency, mode, sent and received exchange — with the header and a check against the specification above it. On Windows, Mac, Linux, a Chromebook or a phone.

No server processing No account No daily limits

What a Cabrillo file is

Cabrillo is the plain-text format amateur radio contest logs are submitted in. A header of lines like CALLSIGN: N0TST, CONTEST: CQ-WW-CW and CATEGORY-POWER: LOW sits between START-OF-LOG and END-OF-LOG, and every contact is one QSO: line — frequency, mode, date, time, your call and what you sent, their call and what you received. The files usually end in .log (sometimes .cbr or .txt); every contest logger writes them, and the organisers’ robots read them.

Being plain text, a Cabrillo file opens in Notepad — but reading hundreds of QSO lines by eye is slow, and a stray error is easy to miss. Here the QSOs become a table you can sort, search and filter, the file is checked line by line, and it saves as ADIF for LoTW, QRZ or a logger, or as a spreadsheet.

What you can do here

Any logging programEach program writes ADIF its own way — field lengths counted in bytes or in characters, Latin-1 or UTF-8, UTF-16 from Ham Radio Deluxe. All of them open with every accent in its place: São Paulo stays São Paulo.

Nothing is lostEvery field is kept, including the ones a program adds for itself (APP_ fields) and user-defined ones, so saving the log again does not drop anything.

Files for radio programming softwareChannel and DMR contact files are made for the radio maker’s software (CPS), not written to the radio. Tested by importing into AnyTone AT-D878UVII CPS 4.00, AT-D878UV (first model) 4.00, AT-D890UV 1.05, AT-D578UV 1.21, AT-D868UV 1.39, AT-D168UV 1.07, BTECH DMR-6X2 PRO 1.22e, OpenGD77 CPS E2026.05.26, Baofeng DM-32UV V1.60, TYT MD-UV380/UV390 CPS V1.06, Retevis RT3S V2.41, Baofeng DM-1701 V1.05, Radioddity GD-77 V3.1.9 and Ailunce HD1 V3.05.

Messy files tooA field with a wrong length, a log that ends without its last end-of-record, the comments LoTW writes after its values — read the way the program meant them.

Convert Cabrillo to something else

Cabrillo→ADIF Cabrillo→Excel

Questions

How do I upload a contest log to LoTW?: LoTW takes ADIF, not Cabrillo. Open the .log here, choose Save log as → ADIF, and sign the .adi in TQSL as usual. Digital (DG) QSOs need their mode set first — Cabrillo does not say which digital mode it was.
Is the log uploaded anywhere?: No. The file is read by the page itself, in your browser; nothing is sent to a server.
Can I fix a Cabrillo file here?: You can save it again as Cabrillo with the header filled in from a form and every QSO line written the standard way. To change a QSO itself, edit the file in a text editor or in your logger.